The following discussion of the background to the invention is intended to facilitate an understanding of the present invention. However, it should be appreciated that the discussion is not an acknowledgment or admission that any of the material referred to was published, known or part of the common general knowledge in any jurisdiction as at the priority date of the application.
LED lighting is advantageous over conventional lighting systems due to the less electrical energy consumed per lumen. However, LED lighting system requires proper control or regulation of electrical current and/or electrical voltage. Most LED lamp systems are driven by electrical drivers that are typically voltage and/or current regulators adapted to suit the voltage and current requirements of LED loads.
Conventional LED drivers may incorporate dimmers (dimmer circuitry) for the control of brightness of LED loads (such as LED lamps) or the switching of the LED lamps on or off. Dimmer protocols include pulse wave modulation (PWM), 1-10V/0-10V VDC dimmer protocol, Potentiometer, and Motion sensor protocol. Potentiometer and Motion sensor are devices widely used for lighting dimming control.
Most conventional dimming systems are binary on/off system and do not allow flexibility in dimming to the required light brightness levels. For example, motion sensor for conventional dimming system is based on the binary On/Off.
Further, for implementation on circuits with primary and secondary sides, dimmers are usually designed with the rectifying side (on the primary). Dimmers at the primary AC side are achieved based on phase cut which will create electromagnetic interference (EMI). Due to EMI, the power factor of these circuits in operation will be affected adversely by a factor of 0.3 to 0.5, resulting in relatively higher distortion compared to non-dimmer controlled system.
Due to the demands for high powered LED lamps, for LED lamp systems comprising one or more high powered LED lamps, each LED lamp is typically controlled by a separate driver. High-powered LED lamps include, but are not limited to down lights; MR16; GU10; flood lamps etc. In such LED lamp systems, AC dimmers may be designed on the primary side, but will have to be in electrical communication with all LED drivers in the system. This is often complex and there will be greater distortion due to EMI may result as more and more high-powered LED lamps (and drivers) get added to the system.
It is an object of the invention to at least alleviate one or more of the above problem(s).